our top 10 - california code compliance, inc. · 9 transformer & motor protection motor type...
TRANSCRIPT
Our Top 10
Most Commonly Found Non-Compliant Items in Industrial
Equipment Examinations
2
Top 10 Trouble Areas
10. Improper Grounding
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Grounding
4
Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring
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Use of Flexible Cords
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring8. Incorrect EMO circuit function
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EMO (Emergency OFF)
RequirementsAll equipment shall be equipped with a “Category 0” stop. (USA, CE)Switches shall be self latching & NC
Must be PUSH to operate buttonActuators shall be colored REDBackground shall be colored YELLOWActuators shall be mushroom-head or palm type
Resetting of switch shall not restart equipmentRequires three step operation:
1. Activate EMO switch2. Reset EMO switch3. Restart equipment
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring8. Incorrect EMO circuit function7. Improper transformer & motor
protection
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Transformer & Motor Protection
Motor Type
Single phaseSquirrel cageEnergy efficientSynchronousWound rotorDirect current
300% 175% 800%
800% 150%
250%300% 175% 800% 250%300% 175% 1100% 250%
NEC table 430.52 sets the over current protection as a % of full load current:Non-Time Delay
FuseTime Delay
FuseInstantaneous Trip Breaker
300% 175% 800% 250%
Inverse Time Breaker
150% 150% 250% 150%150% 150%
Only the primary is protectedBoth primary
and secondary are protected
does not apply
250%
does not apply
125%250% 250% 167%
167% 300%
Current >=9
Current <9
Current >=9
Current <9
Current <2
Note: See NEC table 450.3(B) notes #1-3 for more detail.
Primary ProtectionSecondary Protection
125%
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring8. Incorrect EMO circuit function7. Improper transformer & motor
protection6. Improper wire size & marking
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Wire Size & Marking
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring8. Incorrect EMO circuit function7. Improper transformer & motor protection6. Improper wire size & marking5. Nameplate or Nameplate Information
Missing
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Nameplate
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as
permanent wiring8. Incorrect EMO circuit function7. Improper transformer & motor protection6. Improper wire size & marking5. Nameplate or Nameplate Information
Missing4. Oversize mains & branch breakers
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Oversize Mains& Branch Breakers
If system input is: 208V, 3Ø, andIf branch breakers are:
50A, 3Ø, 3 or 4 pole25A, 3Ø, 3 or 4 pole20A, 2 pole15A, 1 pole (six total)
What is the size of the main breaker (disconnect)?
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Oversize Mains& Branch Breakers
The ampere rating (of the main breaker, if used as a disconnect) shall be at least 115 percent of the sum of the full-load currents required for all equipment that may be in operation at the same time under normal conditions of use.If the branch circuit supplies a single non-motor operated load rated at 16.7 amperes or more, the overcurrent device rating shall not exceed 150 percent of the load rating.
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as permanent
wiring8. Incorrect EMO circuit function7. Improper transformer & motor protection6. Improper wire size & marking5. Nameplate or Nameplate Information Missing4. Oversize mains & branch breakers3. Main CB (disconnect) not listed (UL489)
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Use of Listed Breakers
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Top 10 Trouble Areas
10. Improper Grounding9. Flexible cord (type SO) used as permanent
wiring8. Incorrect EMO circuit function7. Improper transformer & motor protection6. Improper wire size & marking5. Nameplate or Nameplate Information Missing4. Oversize mains & branch breakers3. Main CB (disconnect) not listed (UL489)2. No GFCI on utility & convenience outlets
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Effects of Electric Shock,Charles F. Dalziel, 1956
Bodily Effect Gender DC (ma)
60 Hz (ma)
10kHz (ma)
Men 1 0.4 7Women 0.6 0.3 5
Men 5.2 1.1 12Women 3.5 0.7 8
Men 62 9 55Women 41 6 37
Men 76 16 75Women 51 10.5 50
Men 90 23 94Women 60 15 63
Men 500 100 NDWomen 500 100 ND
Possible heart fibrillation after three (3) seconds
Severe pain,difficulty breathing
Pain, w/ loss of voluntary muscle control
Pain, w/ voluntary muscle control maintained
Threshold of bodily perception
Slight sensation at point(s) of contact
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Effects of Electric Shock
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Effects of Electric Shock
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AND, #1
Manuals and Schematics are
Non-existentor
Incomplete